function S = AIA_step1_S(Delta)
    F = length(Delta);
    S11 = F;
    S12 = cos(Delta);S12 = sum(S12(:));
    S13 = sin(Delta);S13 = sum(S13(:));
    S22 = cos(Delta).*cos(Delta);S22 = sum(S22(:));
    S23 = cos(Delta).*sin(Delta);S23 = sum(S23(:));
    S33 = sin(Delta).*sin(Delta);S33 = sum(S33(:));
    S = [S11, S12, S13;
         S12, S22, S23;
         S13, S23, S33];
end